Hydroaeroplane-boat.



v G. H. CURTISS. HYDROAEROPLANE BOAT. APPLICATION FILED DEC. H. l9l4 1,256,878. Patented Feb.19,1918.

2 SHEETS-SHEET I.

1: u' i H i H i H l H i uf. Suva nim- GLENN HGmzms.

G. H. CURTISS.

'HYDROAEROPLANE BOAT. APPLICATION HLED 050.11. 1914.

1,256,878. Patented Feb.19,1918.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

GLENN H. O'UBTISS, OF HAMMONDSPORT, NEW YORK, ASSIGKOB TO THE CUBTISS MOTOR COMPANY, OF HAMMONDSPORT, NEW YORK, A CORPORATION OF NEW YORK.

HYDROAEROPLANE-BOAT.

Specification of Letters Patent.

Patented Feb. 19,1918.

Application filed December 11, 1914. Serial No. 878,718.

To all whom it may concern:

Be it known that I, GLENN H. CUn'rrss, a citizen of the United States, residing at Hammondsport, in the county of Steuben and State of New York, have invented certain new and useful Improvements in Hydroaeroplane-Boats, of which the following is a specification.

My invention relates to hydroplane boats of the type commonly used in connection with hydro-aeroplanes of the flying boat type. It has for its objects the enabling of the craft to rise quickly from the water with maximum load aboard and having risen from the water to enable operation in the air with a minimum'of. head resistance due to the body of the boat. To these ends the main flotation body of the boat is given a longitudinal section of approximately stream line form, and

a transverse section increasing in size from the head of the boat to a maximum approximately one-third length astern, and thereafter gradually-decreasing in cross section until the tail of the boat is reached. This cross section is approximately the shape of an ellipse with one or both ends or sides cut,

ofl to form the bottom of the boat,or the top thereof, as the case may be. Further I decrease the minor axis of the ellipse more rapidly than the major axis as the cross section is decreased in the immediate vicinity of the tail of the boat, so that the section becomes substantially a straight line terminating in the vertical rudder post. Previous to this, the separate axes are independently varied in the rearward progression of adjacent cross sections, to obtain the streamlines with which the boat is characterized, and to bring out to the fullest extent the features of efficiency above enumerated. The bottom of the boat is stepped and the front portion thereof constitutes the active hydroplaning surfaces, while the rear portion thereof underlying the tail proper makes a salient angle therewith. Preferably the hydroplaning bottom is V-shaped. On the sides of the boat are formed excrescent structures the bottoms of which are in continuation of the hydroplaningr bottom of the boat, and the longitudinal section of which is of stream line form. Preferably these excrescent structures are water tight, and are of an approximately triangular section.

In the accompanying drawings, I show one embodiment of my invention but wish it Fig. 3 is a front elevation thereof show- I ing aerial supporting surfaces attached and,

igs'. 4 to 10 inclusive are transverse sections on lines 4 to 10 of Fig. 1.

10 designates the flotation body of the boat. As clearly indicated in the side elevation and plan of Figs. 1 and 2 this body has a longitudinal section approximately stream line in form. There are a few slight irregularities in its surface, but these are insuflicient to detract from the behavior of the boat in air as a stream line body. The principal variation is at the head or prow of the boat, where the top is cut straight back on the line 11 to form a front deck, and give unobstructed vision from the cabin 12. To complete the elevational streamline the cabin roof line would naturally be downwardly curved to round off into a substantially elliptical juncture with the nose. This forward elevational streamline, however, is

interrupted by the provision of the fore deck 11 which extends horizontally and rearwardly to an intersection with the cabin, a cockpit being provided at the intersection of this deck with the cabin and a conning top having windows set therein being furnished to inclose this cockpit and to round off the interrupted lines of the cabin forwardly. The side and top walls of the cabin merge into the stream line of the body aft as indicated in Fig. 1. Entrance to the cabin is by a hatch door 13 in the top and preferably located beneath the upper aerial supporting surface whereby it is shielded from the weather.

The transverse section of the body of the boat is in the form of an ellipse cut away in some cases at opposite ends of an axis and in other cases at one end only. The section at the front of the boat as clearly shown in Figs. 4 to 7 is in the form of an ellipse cut away at each end of an axis, while the section. at the tail of the boat as shown in Figs. 8 to 10 is in the form'of an ellipse cut away at the lower end of one axis only. In the form shown this axis is the major axis, all

of the major axes lyin in the longitudinal vertical plane of the b y. The cross section increases gradually to a maximum approximately one-third way astern, and thereafter 6 decreases gradually. Both axes decrease proportionately for a part of the rearward distance traversed, then the major axis is shortened at the more rapid rate and finally the decrease of the minor axis of the elliptical section is made more rapidly than that of the major axis. These three successive stages clearl appear from inspection and comparison 0 Figs. 7-8, Figs. 89 and Figs. 91O respectively, the elliptical section eventually becoming a straight line in the rudder post 14. In other words the transverse section may be described as varyingly elliptical, the size of the ellipse (rearwardly from the prow) passing through successive stages in which a) the major axis increases rearwardly more rapidly than the minor axis (6) both axes decreasing rearwardly, and (c) the minor axis decreases at a more rapid rate than the major axis, the said sectional ellipses terminating in a straight line at the rudder post.

The bottom of the boat is stepped as indicated at 15 (Fig. 1). The front portion thereof is of V section the angularity of which increases gradually from the stem 16 to the step 15 as indicated clearly in Figs. 4 to 7. Also it will be observed there is an abruptly increasing and then a gradually decreasing concavity of the opposite sides of the V-bottom merging into the substantially flat salient surfaces at the step 15. It will be observed however, that this concavity is not great in any case, and further that the downward and rearward inclination of the bottom at the keel 17 is substantially the same as that at the chimes 18, excepting at the upwardly inclined prow of the boat which portion of course has no hydroplaning function.

Projecting laterally from the sides of the flotation body 10 at or near the chime lines- 18 are elongated excrescent structures 19. These structures have an approximately stream line form as clearly appears from Figs. 1 and 2. Transversely they are of approximately triangular and varying cross section, one side of the said section being in continuation of the transverse section of the bottom of the boat (see Figs. 6 and 7), whereby their under surfaces constitute con tinuations of themain hydroplaning surfaces, another side conjoining the sides of the main body 10. and the third side extending downwardly and laterally there from. Considering the conjoint sides of the hull and fin excrescences as identical, as is usually the preferable construction, it will be observed that the fins in cross section then become of an acute V-shape, one side of the V lying in the plane of the bottom and the other side intersecting therewith from the hull. These excrescent structures 19. are made watertight independently of the main body 10 and in the embodiment shown are each hermetically sealed. The two structures 19 and the front portion of the main body 10 make a total of three longitudinally extending watertight compartments. The front portion of the main body 10 is further transversely subdivided into watertight compartments as indicated by the dotted line bulkhead 20. The tail portion of the boat' 1s also divided into watertight compartments by transversely extending bulkheads 21.

erial supporting surfaces 22 extend laterally from the body 10 as indicated. In the preferred form of my invention, there are provided a multiple number of these surfaces In superposed I'GlatiOIlcOIlStitlltiIlg the cell of a biplane or triplane as the case may be.

The fins 18, it will be observed, extend considerably beyond the center of the wings and therefore the hydroplaning area and lift is augmented in the neighborhood of the center of gravity and center of pressure as it should be. This location of the fins 18, although most effective, after having gained he surface of the water, is of little import ance in gaining this end. More important is it that the fins should be located in the vicinity of the resultant center of hydroplane lift so that the hydroplane lift will be increased at the point where it is most needed to be lncreased and at a point providing for quick rise from a submerged position at rest to a hydroplaning position upon the surface of the water at speed. The great advantage in solocating the fins is that the enormous thrust value occasioned by the elevated location of the motor or motors (not shown) is offset and the boat prevented from nosing under when coming to a hydroplaning position and when hydroplaningespecially when traveling at comparatively slow speed. In explanation, it is to be noted that three working forces are in evidence, to wit: gravity, thrust and hydroplane lift. Unless the hydroplane lift is sufficient to counteract the force of thrust, then the boat will have a tendency to plane with its nose low in the water. Were the fin excrescences omitted, the size of the fore body of the hull would have to be materially increased so that the hydroplaning area mightbe proportionately enlarged. Thi is objectionable because of the added weight and increased resistance during flight. The resultant center of hydroplane lift is shown by calculation to lie approximately one-third back of the forward end of the hydroplaning surface.

With this understanding of the structural embodiment of my invention, it will be clear that I have attained the objects thereof. The extended and very large hydroplaning aaeasvs surfaces provided by the bottoms of the excrescent structure 19 in conjunction with the main body 10 are of suflicient size to enable the body to come rapidly to its hydroplaning position and to rise from that position into the air with maximum load. In a. recent trial, over a ton of useful load was lifted from the water in a run upon the surface not exceeding five hundred feet. The flying boat took to the air with great ease. As the head of the boat is pointedly upwardly for the craft to take to the air, the tail, which until then is clear or substantially clear of the Water is carried downwardly into contact therewith, the boat being as it were rocked about the step 15 as a pivot. This assists in enabling the boat to rise easily from the surface of the water by reason of the increased flotation and additional planing surface provided at the critical point in the operation. When the craft is in the air, the longitudinal stream line formation of the excrescences 18 prevent them from materially increasing the head resistance of the boat. Under actual flying conditions it was found that they produced no noticeable retarding efl'ect. Of course the longitudinal stream line section of the body as a whole is productive of the same excellent results obtained in prior flying boats of my invention.

While on the surface of the water (or in the air for that matter, the operator has an excellent footing on the flat deck 11 and its form and location are especially adapted for the mounting and operation of machine guns for military purposes. The operator further has at all times unobstructed vision ahead directly over the flat deck 11, which forwardly mutilates the generating boat line of the cabin which would normally round off into the nose of the body.

The sealing of the excrescent structures 18 independently of the main body 10 gives to them the additional and very important function of water tight compartments. They are located at a point Where these compartments are very much needed, directly opposite the cabin 12. It is of course not practicable to seal the cabin section. The flotation of this section of the boat is thereby materially raised and is assuredly of sufficient value under all conditions of service.

I claim:-- 7

1. An aeroplane body comprising a main flotation body, the bottom of which is shaped to form hydroplane surfaces, and forwardly located marginal excrescent structures on the sides of said main flotation body, the bottoms of which are coextensive with and in continuation of the hydroplaning of said bottom. 7

2. A hydroplane boat comprising a main flotation body, the bottom of which is shaped to form hydroplaning surfaces, and marginal said bottom later-11H excrescent structures on the sides resultant center of hydroplane lift as riderof said flotation body, extending longitudinally substantially the length of said hydroplaning surfaces and having their gems in continuation of said hydroplane suraces.

3. A liydroplane boat for hydroaeroplanes comprising a main flotation body, the bottom of which is shaped to form hydroplaning surfaces, and forwardly located excrescent flotation bf in'iangular cross section on the sides of said flotation body opposite the resultant center of aeroplane lift, one side of said secfion being in core tinua 'on of the transverse section of the bottom of the boat, another side parallel to the side of the main body, and the side extending laterally, and downwardly from a point on the side of the boat intermediate the chime and the gunwale.

4. A hydroplane boat body having an interior water-tight the flying crew or other useful load together with waterfight fin excrescences arranged to flank said space in the of the bottom of the boat, the excrescences conjointly functioning as surfaces and as lateral water-tight comparhnents protecting said space.

5. A hydroplane boat body having an interior watertight space for occupancy by the flying crew or other useful load together with watertight compartments respectively ahead of, aft of, and at each side of said space, the side compartments being in the form of fin excrescences arranged to extend out laterally from the boat body proper to augment the hydroplaning area thereof.

6. A flying boat adapted to travel upon the surface of the water, rise therefi'om and travel through the air, comprising a hydroplaning bottom surface laterally extended beyond the plane of the gunwales of the boat body proper by flu excrescences arranged at opposite sides of aid body principally ahead of the center of gravity of the craft, the corresponding surfaces of said excrescences a dihedral angle with the vertex thereof in the vertical plane of the keel line of said boat.

7. In a hull for flying boats, a V-shaped hydroplaning bottom and acutely V-shaped planing fins, each tin having one side formed in. the plane of one of the V-sides of the tom.

8. In a hull for flying boats, a V-shaped hydroplaningb of said bottom f beyond the huh and second ces pro jectmg' from the sides of the hull for inter-' section with the first said sin-hm 9. Aflying boat -r a mam flotation body having a bottom, and fin excl-memes arranged to augment y in the vicinity of the space for occupan y by integral confinuations mined through hydroplaning action on the surface of the water and preparatory to flight.

10. In a hull for flying boats, a V-shaped hydroplaning bottom and auxiliary planing fins formed as lateral extensions of said bottom, said fins being enlarged rearwardly from the bow of the hull in directions providing longitudinal and transverse stream- 11. In a flying boat, a hull rounding ofl rearwardly from its bow to provide a hydroplaning bottom and rounding ofl' oppositely to provide a cabin situated over said bottom, and a fore deck for the hull intersecting the generating hull lines for the cabin.

12. A hull for flying boats enlarging rearwardly along rounded, upper and lower longitudinal hull lines, a hydroplaning hottom for the hull merging into the lower hull lines, and a deck intersecting the upper hull lines for provision of a cabin over said bottom.

13. In a flying boat, a hull, a cabin having streamlines merging integrally into the bull in one direction and a conning top rounding oil the streamlines of the cabin in the other direction.

14. A hull for flying boats having its elevational aspect determined by lines rounding ofl' rearwardly both upwardly and downwardly from the nose of the hull, and a deck intersecting the said upper boat line and cutting down the hull to provide a cabin.

15. In a hydroplane hull, an overhanging bow having an elevational aspect determined by lines rounding ofl' rearwardly and downwardly, a bottom V-shaped in cross section, the angled portions of the bottom having their inception at the bow and considerably above the water line, each portion being decreasingly concaved from the nose rearwardly and the angle between the portions rearwardly, approaching a maximum obtuseness, and a step terminating said bottom.

16. In a hydroplane hull, a fore-body, a tail, a planing step dividing the bottom of the fore-body from the tail bottom, an upper surface for the tail enlarging forwardly in a reverse curve over said step and a cabin roof provided over the fore-body in advance of said step and merging into said enlarging tail surface.

17. In a hydroplane hull, a fore-body, a tail, a planing step dividing the bottom of the fore-body from the tail bottom, an upper surface for the tail enlarglng forwardly in a' reverse curve over said step to form a cabin roof for the fore-body and a deck intersecting said fore-body at a distance below said roof and destroying a normal merging of the roof-line into t e nose of the hull.

18. In a hydroplane hull, a fore-body, a tall, a cabm provided for said fore-body and having a roof merging rearwardly into said tail and forwardly into the nose of the hull, a deck intersecting the cabin and a cockpit provided at the intersection of said cabin and deck.

19. A flying boat including a flotation body having an underneath hydroplaning surface of a size in cross section designed to extend out on either side beyond the boat body proper approximately opposite the center of hydroplane lift, the bottom surfaces of the laterally extended portions making a dihedral angle with the vertex of the angle in the vertical plane of the keel lineof the boat.

20. A flying boat including a main flotation body having an underneath hydroplaning surface of substantially V-form in transverse section, fln excrescences arranged to augment the hydroplaning surface later ally in the vicinity of the resultant center of hydroplane lift, the bottom surfaces of the fins continuing uninterruptedly the hydroplaning bottom of the boat body proper.

21. A flying boat including a main flotation body, a hydroplaning under surface, and lateral extensions of a constructon designed to conform longitudinally to said hydroplaning under surface and to extend substantially the full length thereof.

22. In a hydroaeroplane boat body, a bottom longitudinally convexed, and auxiliary planing surfaces formed as lateral extensions of said bottom in the vicinity of the resultant center of hydroplane lift, said center lying considerably in advance of the point of maxlmum convexity, and snfliciently distant therefrom to provide for its movement rearwardly to a point in the vicinity of said point of maximum convexity upon fore and aft oscillation of the boat.

23. In a hydroaeroplane boat body, a hottom longitudinally convexed, aeroplanevance of the resultant center of hydroplane lift and terminating rearwardly in the vicin-- ity of said point of maximum convexity.

24. In a flying boat, a main flotation body, a hydroplaning under surface, fin excrescences coextensive with the hydroplaning surface, each fin extending forwardly beyond a line in the vertical plane of the resultant center of hydroplane lift a greater distance than to the rear thereof.

25. A flylng boat including a forward hydroplaning bottom designed to extend from end to end uninterruptcdly and at an angle laterally'be'yond the sides of the boat body proper to materially increase the hydroplanng surface and enable the boat to come rapidly to lts hydroplaning position upon the surface of the water and to rise from that position into the air.

26. In a hydroplane boat, a bottom longitudinally convexed, and auxiliary planing surfaces formed as lateral extensions of said bottom to extend substantially the full length of that portion of said bottom ahead of a point determining the maximum convexity thereof.

27. In a hydroaeroplane flotation body, a longitudinally convexed bottom in which that portion of said bottom in advance of the point of maximum convexity is of hydroplaning form, fin excrescences arranged to augment said bottom laterally in the determining vicinity of the resultant center of hydroplane lift, aeroplane wings, the center of pres sure onsaid wings being disposed in the approximate transverse vertical plane of said point of maximum convexity, and said point the rearward terminus of said fins and the rearmost point to which the center of hydroplane lift may be shifted as the body in its entirety is oscillated fore and aft. In testimony whereof I aflix my signature in presence of two witnesses.

GLENN H. CURTISS. Witnesses:

H GENUNG. 

